​What are the installation precautions for a pipeline pump?

A pipeline pump is a type of single-stage or multi-stage centrifugal pump designed for direct installation into a pipeline. It comes in two main configurations: vertical and horizontal. The term "pipeline pump" most commonly refers to the vertical type, as its inlet and outlet are aligned on the same straight line and are of the same diameter, making it ideal for in-line boosting applications. Hence, it is also known as a booster pump. The horizontal pipeline pump, while also featuring same-diameter inlet and outlet, has them arranged at a 90-degree angle to each other.

Installation Precautions for Pipeline Pumps  

1. Mismatched pipelines  

Some users of pipeline centrifugal pumps think using a smaller pipe can boost the actual head, but here’s the truth: a pump’s actual head = total head ～ head loss. Once the pump model is fixed, its total head is set. Head loss mainly comes from pipeline resistance—the smaller the pipe diameter, the greater the resistance, and thus the larger the head loss. So, downsizing the pipe won’t increase the actual head; instead, it’ll lower it, dragging down the pump’s efficiency.  

Similarly, using a larger pipe with a smaller-diameter pump won’t reduce the actual head. In fact, the reduced pipeline resistance cuts head loss, slightly boosting the actual head. Some users worry that a larger pipe will overwork the motor, thinking the increased water in the pipe presses harder on the impeller. But that’s a myth—this doesn’t actually hike up the motor load.  

2. Using a high-head pump for low-head pumping  

Some users assume lower pumping head means less motor load. Guided by this mistake, they often pick pumps with excessively high head. But for centrifugal pumps, once the model is set, power consumption ties directly to the actual flow rate. Flow decreases as head rises, so higher head means lower flow and less power used. Conversely, lower head brings higher flow—and higher power consumption.  

3. Too many elbows in the inlet pipeline  

Elbows in the inlet pipe add local water resistance. What’s more, elbows should only turn vertically, never horizontally—horizontal turns trap air, which spells trouble.  

4. Inlet pipeline’s horizontal section is flat or slopes upward  

This traps air in the inlet pipe, weakening the vacuum in the pipe and pump, reducing suction head, and cutting water output. How to address this? The horizontal section should slope slightly toward the water source—no flatness, let alone an upward tilt.  

5. Pump inlet connects directly to an elbow  

This makes water flow uneven when entering the impeller. If the inlet pipe is larger than the pump’s inlet, install an eccentric reducer—with its flat part up and sloped part down. Otherwise, air builds up, reducing output or stopping water flow entirely, often with clunking noises. If pipe and pump inlet diameters match, add a straight pipe between them—at least 2–3 times the pipe diameter in length.  

6. Pump outlet sits above the outlet pool’s normal water level  

This raises head but cuts flow. If terrain forces the outlet above water, add an elbow and short pipe to create a siphon, lowering the outlet height.  

7. Wrong position for the inlet pipe’s water intake  

- The intake is too close to the inlet pool’s bottom or walls—less than its own diameter. If the pool bottom has sediment, an intake less than 1.5 times its diameter from the bottom will clog or suck in debris, blocking water flow.  

- The intake isn’t deep enough in the water. This causes swirling on the water surface around the intake, disrupting flow and reducing output. The correct depth? At least 300–600mm for small to medium pumps, and 600–1000mm for large ones.  

8. When a foot valve is installed, the bottom section of the inlet pipe isn’t vertical  

A non-vertical setup stops the valve from closing properly, leading to leaks. The fix: the section with the foot valve must stand straight. If terrain makes vertical installation impossible, the pipe axis should angle at least 60° from the horizontal.